Rheostat



B. F. GARDNER.

BHEOSTAT.

APPLICATION mu: SEPT. :9. ma.

1,310,696. Patented July 22, 1919.

UNITED STATES PATENT OFFICE.

BENJAMIN FULTON GARDNER, OF CHICAGO, ILLINOIS, ASSIGNOR 0F ONE-HALF T0SEYMOUR STEDMAN, OF CHICAGO, ILLINOIS.

nHEosrA'r.

Application filed September 19, 1918.

To all whom it may concern:

Be it known that I, BENJAMIN FULTON GARDNER, a citizen of the UnitedStates, residing at 160 North Wells street, Chicago, in the county ofCook and State of Illinois, have invented a certain new and usefulImprovement in Rheostats, of which the following is a full, clear,concise, and exact description, reference being had to the accompanyingdrawings, forming a part of this specification.

My invention relates to im rovements 1n rheostats and particularly to te class of socalled lamp dlmmers, and my object is to provide means by,whilch incandescent lilment lamps of any make are operable at fullcandle power, or dimmed to a glow of any degree desired. The inventionmay also be used with an attachable plug and conductor cord, in circuitwith small motors and other types of translating devices to regulate andcontrol the current within the system.

The invention will be fully understood from the following specificationtaken in connection with the drawing which represents in section and indetail a device in accordance with the invention.

Referring to the drawing, Figure 1 is a vertical longitudinal sectionalview of the invention and Figs. 2, 3, and 4 illustrate details ofconstruction.

Like numerals in the specifications refer to like numerals in thedrawing.

The numeral 6, designates the exterior part of a lamp receptacle, andthe figure 7, indicates the flange part of the receptacle supporting themetal electrodes 8, and 11.

The screws 10, serve to unite the male metal electrode 9, to the femaleelectrode 8, firmly fixing the upper electrode to the lower electrodemechanically and electrically. These electrodes are of the standardscrewthreaded type.

The numeral 16 designates a cylindrical cup-like part of porcelainhollow within and screw-threaded upon its exterior, with a hole in thebottom. This part 16 is attached to the apparatus by screwing it intothe screw-threaded electrode 9.

In Fig. 1, and Fig. 4, the numeral 16, designates washer-like rings ofelectric resistan'ce material. These rings are placed within the cup16*- and superimposed one upon another.

The numeral 15,111 Fig. 1, and Fig. 3, in a Specification of LettersPatent.

ceptaele part of the plug.

Patented July 22, 1919.

Serial No. 254,837.

tube or sleeve of insulating materialglass preferable,which serves toinsulate the resistor element 16, from the metal electrode 13.

The numerals 12, 13, and 14, in Fig. 1, and Fig. 2, designate theseveral parts of the plunger electrode which supports the resistor rings16, and also serves as a shunting device when in contact with the fixedelectrode 11. This plunger electrode consists of three distinct parts,all of which are integral and readily made of one piece of metal in alathe or screw machine. The part 14., of this plunger electrode looselyextends through the hole in the bottom of the cup part 16*. Within thecup the part 12, of this electrode is fashioned like a rivet head, whichforms a seat for the resistor rings, and keeps the plunger electrodefrom falling out ofthe cup 16 when the plu is not in service. The part13, of the plunger electrode is utilized as a shunting device when fulllight of the lamp 's requlred.

In Fig. 1, the nume als 17, 18, 19, 20, 21 and 22, designate the detailsof a conventional socket and the numeral 23, designates an electricincandescent lamp of the standard type. As no claim is made for eitherlamp or socket further description is unnecessary. However, electrode 19must be rigidly fixed in order to resist displacement under pressure.

In the explanatory matter regarding the operation of my invention and tomake more clear the claims which follow, I shall use the term plug, toinclude the parts numbered, 6, s, 9, 10, 11, 12, 1s, 14, 15, 1 6, and1:6. The term socket, will include the parts indicated by the numerals,17, 18, 19, 20, 21, and 22. While the device is not 0 erable unlessattached to a conventional soc (ct, the plug, is manufactured andmarketed as a complete article suitable for use in any standardreceptacle or socket.

The operation of my invention is exceedingly simple. Insert the lampinto the re- Insert the plug into a h wall -socket or other receptacle.When the central electrodes of the plug and socket are in contact if thecurrent is on the lam will glow dim. A further half turn of t e plugwill cause the lam "to glow at full candle power. When the limp isfirmly seated it can be used as a handle to oper ate the plai er, graspthe lamp recap tacle parl of the plug and a partial turn in or out willeffect the object desired. When the electrodes of plug and socket are incontact, the central plunger electrode may be regarded as stationary.Not so with the plug 710/ 80, for it can move to the limit of its screwthread. The resistor rings are mounted upon the plunger electrode, andin contact with the upper electrode 11, which is immovable and fixed inthe part (3. The action is similar to that of a vise, in which theresistor rings are held and compressed. Suflicient compression effectedby the further screwin of the plug into the socket causes the plungerelectrode to make contact with the upper electrode 11. When thusadjusted the electric current has two paths, 2'. 0., through theresistor rings and through the plunger electrode which may be regardedas a shunt; in this state the resistance is nil and the lamp will be atfull glow. Relieve the compression of the re sister, the shunt contactis broken, and the lamp will glow dim. A partial reversing turn of theplug will leave the artificial re sistance in circuit and disrupt theshunt contact. The degree of compression of the resistor rings changesthe conductivity of the system and several degrees of luminosity mziy beobtained.

t should be understood that the structure described by thisspecification is illustrative only and for the purpose of making myinvention more clear, and that I do not re gard the invention as limitedto any of the particularities of construction chosen for the purposes ofillustration, except in so far as I have included such limitationsWithin the terms of the following claims.

What I claim is: 1. In a rheostat of the class described, a combinedsocket, plug and receptacle comprising the female threaded electrode ofthe socket part directly connected to the male threaded electrode of theplug part and a cylindrical insulating part screwed into the electrodeof said plug part, and means with in said cylindrical insulating part ofsaid plug part operable by said combined socket plug and receptacle toregulate and control an electric current for the purpose specified andsubstantially as described.

2. In a rheostat of the class described, a combined socket plug andreceptacle, comprising the male and female threaded elec trodes of saidsocket and plug parts directly connected, a cylindrical insulating partsup ported by the screw-threaded electrode oat said plug part and anelectric resistor element within the cylindrical insulating part of saidlug part and means operable by said com ined socket, plug and receptacleto regulate and control an electric current for the purpose specifiedand substantially as described.

3. In a rheostat of the class described a combined socket, plug andreceptacle, the male and female electrodes of said socket and plug partsdirectly connected, an insulating cup within the electrode of said plugpart, an electric resistor element within the insulating cup of saidplug part and a metal plunger within the insulating cup of said plugpart and operable by the reciprocating movement of the several parts ofthe said combined socket, plug and receptacle, whereby an electriccurrent is regulated and controlled.

4. a rheostat of the class described, a cylindrical cup-like insulatorcontaining a three part plunger, said three part plunger operable as anelectrode to conduct electric current, to shunt electric current, andcompress resistance material within said cylindrical cup-like insulator.

In a rheostat of the class described, an electric resistance elementcomprising multiple parts mounted upon a plunger, and means operable bythe several parts of said rheostat, whereby said resistance element iscompressed and the ends of said plunger are forced to make directcontact with the central electrodes of the socket part and thereceptacle part of said rheostat.

6. In a rheostat of the class described a combined socket and plug, thesocket part of said combination comprising an exterior insulating partand an interior screwthreaded electrode, mechanically and electricallyunited to the exterior screw-threaded electrode of the plug part of saidcombination, a fixed electrode centrally located in the bottom of saidsocket part and a cylindrical insulating part inserted in and supportedby the screw-threaded metal electrode of said plug part, a resistanceelement within said cylindrical insulating part, a plunger electrode oneend of which extends through a hole in the bottom of said cylindricalinsulation and is free to move therein, said resistance element threadedupon the stem of said plunger electrode and seated upon the enlar edsection of said plunger electrode and an insulating sleeve mounted uponthe stem of said plunger electrode and a receptacle with a rigidly fixedcentral electrode all for the purposespecified and substantially asdescribed.

In witness whereof I hereunto subscribe my name this 12th day ofSeptember, A. D. 1918.

BENJAMIN FULTON GARDNER. Witnesses:

E. J. BOILEAU,

FRANK E. STEDMAN.

emu arm Intent-1min nlmtmlror ave -mt: am, Minimums: the *"Gmmlsmw a:mum.

Washington, D. 0-

